In recent years, a laser machining device, a microscope, or the like using ultrashort pulsed light having a very short time width such as on the order of attoseconds to nanoseconds has been developed. Further, an information communication system using a nonlinear optical effect has been developed. For example, in such technical field, it is preferable to generate ultrashort pulsed light having a desired time waveform.
The desired time waveform of the ultrashort pulsed light is obtained, for example, by causing light having various wavelength components to overlap and adjusting a phase of each wavelength component. In order to more accurately realize the desired time waveform, a time waveform of generated ultrashort pulsed light may be measured, and a result of the measurement may be fed back for adjustment of the phase of each wavelength component. Patent Literatures 1 and 2 disclose waveform reconstruction devices for accurately measuring a time waveform of ultra short pulsed light.